Investigation of temperature distribution and coefficient of friction on friction pairs of C/C-SiC disc and copper-based brake pad for high speed train

The coefficient of friction (COF) and temperature distribution of the friction pair composed of carbon fiber reinforced silicon carbide composite (C/C-SiC) brake disc and copper-based powder metallurgy (PM) brake pad are related to its practical application. In this study, for C/C-SiC brake disc and copper-based PM brake pad, TM-I type reduce-scale inertial braking dynamometer was used to test the changes of COF and brake temperature under the conditions of pressure 0.38∼0.75 MPa and speed 120∼200 km/h. At the same time, ADINA finite element software was used. The characteristics of braking temperature field are calculated. The test results show that with the braking speed increasing from 120 km/h to 200 km/h, the average COF increases from 0.244 to 0.371 and the maximum disc temperature increases from 208°C to 446°C under 0.38 MPa. Under 0.57 MPa, the average COF increases from 0.28 to 0.381, and the maximum disc temperature increases from 284°C to 492°C. Under 0.75 MPa, the average COF increased from 0.29 to 0.325, and the maximum disc temperature increased from 337°C to 507°C. The COF does not decrease with the increase of speed due to the good high temperature resistance of C/C-SiC. The disc surface temperature of the test is 7–29% higher than that of the calculation, which is due to the temperature concentration caused by localized contact in the test, making the temperature higher than the theoretical value.